1. Field of the Invention
The present invention relates to a structural technique of a dust filter, especially to a dust filter mounted in a semiconductor waste gas treatment equipment.
2. Description of Related Art
In conventional semiconductor processes, many harmful waste gases, such as, a monosilane, a chlorine gas, perfluorinated compounds, etc, will be produced. In order to prevent the waste gases from damaging external environment and public benefits, the damaging substances in the waste gases should be cleaned and removed so as to be emitted into the external atmosphere.
For conventional methods for treating a waste gas in a semiconductor process, the waste gases are injected into a waste gas treatment equipment, burned in high temperature flame and mixed with a high temperature gas to form a high temperature waste gas and to force the damaging substances in the high temperature waste gas into catalytic transition of high temperature, and decomposed into non-harmful substances. Thus, the water soluble harmful substances, such as, Chlorofluorocarbon, etc, in the waste gas are dissolved in water by using a sprinkling device in the waste gas treatment equipment, and the waste gas is transformed into non-harmful gas. After the gas is cooled to be emitted into the external atmosphere, the environment is polluted. Generally, before the gas is emitted into the external atmosphere, it is necessary to screen the gas by using a dust filter so as to eliminate and remove water molecular and dust in the gas.
For the current treatment techniques, the dust filter is generally a so-called cyclone filtering device. The gas is passed through the cyclone filtering device to use centrifugal force and inertia produced by a whirl rotation in the dust filter. The water molecular and dusts in the gas are separated from the gas by using a principle saying that both a specific density of the water molecular and a specific density of the dust are higher than that of gas so as to remove the water molecular and the dusts from the gas.
Because we want to obtain better effects of filtering the water molecular and the dusts from the gas by using the cyclone filtering device, an air blower is needed and a vortex air guide channel having a complex structure is needed to be constructed. Thus, gas is driven and forced to flow through the vortex air guide channel by means of the air blower to filter the water molecular and the dusts from the gas. However, it is not easy to clean the cyclone filtering device because the structure of the cyclone filtering device is too complex.